But the Code is always seen in London as a 'work in progress'. A spate of recent corporate governance issues involving new arrivals to the London stock market has concentrated minds on whether change is needed.

Corporation (ENRC) set up by eastern European oligarchs, is about to delist from the . Its exit from the UK stock market will come after regular rows between its board of directors and founding shareholders over corporate governance standards were aired in public during its six- year life as a UK listed company. ENRC continues to face a barrage of questions including a recently announced criminal investigation by the Serious Fraud Office.

Later this month the UK listing authority is expected to publish plans on tightening the requirements for listing on the London Stock Exchange. It is just one step in multiple efforts to shore up standards and reaffirm the credibility of doing business in London. There has been concern about damage that may have been caused by overly 'light touch' regulation designed to attract as much foreign capital as possible.

Against this backdrop, the essential 'Britishness' of 'comply or explain' is coming under question as being too 'gentlemanly' and perhaps no longer fit for purpose. Ken Olisa, chairman of Restoration Partners, the merchant bank and a non-executive director who was dramatically ousted from the ENRC board in 2011, made headlines then for describing it as 'More Soviet Than City.' Today he is leading an initiative to consider the need for a new 'corporate governance index' to better police the fundamentals of 'comply or explain.'

"Our code of corporate governance in the UK has been our biggest competitive advantage over the last 20 years, but it needs policing. At the moment it's like telling people there's a 'speed limit' without telling them exactly what it is - if you're not British, you don't understand it being about behaviour, not rules" says Mr Olisa.

A paper drawn up by Manifest, the proxy voting agency and a leading source of governance intelligence and data, has explored the notion of drawing up a 'good governance index.' Sarah Wilson, Manifest CEO, says that although markets talk a lot about 'good governance', it might be time to talk about 'sub-prime governance' ie governance that is sub-optimal and merely provides lip service, ignoring investors' engagement.

The point of a 'good governance index' would be to raise the bar by creating a new index allowing in companies that demonstrate a blend of corporate governance, remuneration governance and sustainability, among other things. Discussions are planned soon with a number of stakeholders, including the Institute of Directors, headed by Simon Walker.

The UK is not alone here. The idea of a 'good governance index' has been widely explored by the World Bank and IFC, which has looked at it in detail. Since 2001 eight stock exchanges around the world have launched corporate governance indexes. They are: Brazil, China, Italy, Mexico, Peru, South Africa, South Korea - and Turkey. The paper explores how they offer a market solution to address any shortcomings in governance.

A new index in the UK may emulate some of the characteristics of The FTSE4Good index, which has been one that has incorporated Environmental, Social and Governance (ESG) risk and performance of companies worldwide. But interestingly, the future determination of that index appears to be uncertain as it has just ended its relationship with the Ethical Investment Research Service (Eiris), the body that has provided research for its FTSE4Good index over the past 12 years. There has been no announcement as yet as to who will step into the breach.

A new corporate governance index could potentially also take into account progress on wide boardroom diversity in listed companies of gender, ethnicity and sexuality - an issue identified as critical by both the UK government and senior business leaders. These are exciting times for UK corporate governance.